The present invention relates to a method for forge welding or the like of a first and a second metal part, wherein at least one joint is established between opposed bounding surfaces on the two parts to be joined, and wherein preferably a reducing gas is passed through the joint or joints before the parts are pressed together.
Such a method is known e.g. from the Applicant's U.S. Pat. Nos. 4,566,625 and 4,669,650, which hereby are incorporated by reference. In the known method a reduced cross-section of the parts to be joined is used in the joint area between the parts in order to obtain a triaxial stress condition during the welding. This results in a pressure in the joint area which is several times higher than the uniaxial yield stress of the material at the temperature in question, with a consequential quicker and better diffusion.
It has now surprisingly been found that an equally good triaxial and pore closing forge welding operation may be performed in a new and simplified manner particularly suited for non-rotation symmetrical joint surfaces.